Mechanism for controlling electric circuits



F. B. LITTLE March 11, 1947.

MECHANISM FOR CONTROLLING ELECTRIC CIRCUITS Fil ed Spt. 11, 1943 2 Sheets-Sheet 2 INVENTOR.

Patented Mar. 11, 1947 UNITED STATES PATIENT OFFICE MECHANISM FOR CONTROLLINGELECTRIC CIRCUITS Frederick B. Little, Chicagoflll.

App ication September 11, 1943,.Serial No..501,951

7'Claims.

1 This invention relates to timing mechanism adaptable to a wide variety of uses, and it is illustrated herein as embodied in a device for controlling radio receivers or other electrically operated devices so as to energize the same at a predetermined time, or for controlling an alarm device to be operated at a given time.

One object of the invention is to provide a relatively simple and compact time-controlled switch device for operating a radio receiver or other electrically energized apparatus in accord- .ance with a predetermined program.

Afurther object of the invention is to provide a timing mechanism suitable for .use with an alarm device, and adapted vto be constructed vmainly of non-metallic materials which are relaranged ina circular seriesto receive one or more contact plug elements arranged to cooperate with fixed contacts for closing a circuit at predetermined times as the dial is rotated by a timed mechanism, such as a synchronous motor.

More specifically, it is an object of .the invention to provide a time-controlled -mechanism which may be interposed between a source of current supply and a radio receiver or other electrically operated device, .adapted to operate from said current source, so that the mechanism shall energize the electrically operateddevice, at a predeterminedtime, as desired, theconnections being readily detachable to permit the substitution of a buzzer or other electrical .alarmdevice for a radio receiver to be operated .at 'a predetermined time in accordance withthe preference of the user.

Other objects and advantages of the invention will become readily'apparent from the following description taken in conjunction with the drawings in which:

'Fig, 1 is a perspective view showing, 'principally, the front face of a timing device embodyin this invention.

Fig. 2 is a vertical sectional view'taken as indicated at line 22 on Fig. 1.

Fig. 3 is a rear elevation of the ,timingmechanism in its case, showing it onasomewhat small- .er scale than in Fig; 1.

"4 is.a verticalsectional'view taken asin- .dicate'd at lineL-d, on Fig. 2.

iFig. 5v is a plansection takenas indicated at line 5-'5..on"Fig. 4.

Figs. I6 and 17 are fragmentary detail views showing the switching mechanism at successive positions in its. cycle .of operation.

Fig. 8 is .a perspective view of.a buzzer including a suitable attachment plug'for connection into the circuit of, the timing mechanism.

Fig.9 is a detail perspective view of .a contact ,plug element for use with the program dia1 of the timing mechanism.

,Fig..l0 is a wiring .diagramof' the "device. While theinvention'is susceptible of various modifications and alternative constructions, -the embodiments .shown .in the drawings and 'described hereinafter are by way of preferred illustration only, .and it'is not intended that the invention be limited thereto or thereby, but it is theintention to cover all modifications and alternative constructionsjfalling within the scope of theflinventon asdefined by the claims.

The mechanism embodying this. inventionis preferably providedwith an enclosing casing I, having a front wall 2 in which a circular opening '3 is formed to accommodate the program dial plate 4 which is mounted for rotation in this opening. Sufficient .clearance is provided between the rim of the opening 3 and the periphcry of the plate ,4, as indicated at 5, so that there is no contact between these parts. ,The dia1 plate 4 .iscarried'for rotation on the'outer end of a shaft "6, which isseen in Fig. 2, provided with a stop collar 1 at its inner end and journaled inside the casing l, in upright bars 8 and 9, spaced apart on mounting posts Ill, H] which extend inwardly from the .front wall '2 of the casing. Within the casing an upright plate or panel ll supports a synchronous. electric motor unit, indicated at l2, and in" the particular form of the invention which is herein illustrated, it may be understood that there is included within the housing of the motor unit suitable gearing which drives a shaft 13 at. aspeed of one revolution per minute.

The shaft 13 carries a worm l4 which is shown in Fig; 5 meshing with a Worm gear 15. The gear i5 is carried on-oneend of a shaft l6 journaled ina yoke l1 and provided with a worm I8 which, in turn, mesheswith a worm gear! 9,.having ahub pinned .-to.the shaftfi. .The gear ratios/are such that the shaft .l3,.running at 1 R..P..M., rotates the. shaft T 6 ..and the dial 4 thereon through one revolution inv each twelve hours. Obviously, if

3 preferred, the ratio could be changed to make the dial 4 turn once in each twenty-four hours, and the dial could then be graduated to indicate hours from one to twenty-four, or to indicate two series of hours, from one to twelve, corresponding to night and day periods.

The drive connection between the shaft 6 and the dial plate 4 is arranged to permit setting the dial, as may be desired. A disk 20, serving as a knob for this purpose, is shown secured to the central portion of the dial plate 4 by means of screws 2| extending through spacer sleeves 22. The rear face of the dial is directly contacted by a fiat ratchet wheel 23, which is driven by the shaft 6. A resilient spider 24 is fixed to the shaft 6 by a set screw 25 in its hub 23, and is engaged with the ratchet wheel 23 by prongs or lugs 21 entering holes 28 in said wheel 23. The resilience of the spider serves to hold the dial plate 4 firmly between the flat face of the ratchet wheel 23 and the opposing face of a flange or washer 65* secured to the outer end of the shaft 3, while a spring pawl 29, attached to the rear face of the dial 4, provides a driving engagement with the ratchet teeth of the Wheel 23. This permits the plate 4 to be turned in clockwise direction for adjusting it to show correct time, but prevents it being turned manually in the opposite direction.

Within the casing I, and accessible through arr opening in the back wall 3! thereof, there is mounted a circuit terminal fitting or outlet 32 adapted to receive the prongs of a connecting plu 33, as seen in Fig. 3; and it may be understood that the wires 34, leading from the plug,

33, are lead-in wires of a radio receiving set or other electrically operated device. The synchronous motor unit 32 is wired for operation from the ordinary house-lighting circuit, and its lead-in wires comprise a cable 35 terminating in a standard attachment plug 36. By means of suitable connections within the casing I, the conductors of the cable 35 are branched so as to supply current to the motor unit l2, and also to the outlet 32 under control of switching mechanism associated with the dial 4, and about to be described. One of the branch wires leading from the cable 35 is indicated at 31 in Fig. 4 as ex- I tending to a member 38, which is one of two adjacent contact members 38 and 39, mounted on the inner face of the front wall 2, and which, under certain conditions, are bridged by a metallic pin or plug 43. A wire 4! leads from the other contact member 39, and as indicated in the wiring diagram, Fig. 10, this wire M is connected to a contact point 42 of a manually operable switch 43. The movable switch arm 44 is connected by a wire 45 to one terminal 46 of the outlet 32, while the other terminal 41 is connected to a wire 48 which is the other branch wire leading from the supply cable 35. Thus, when the switch arm 44 is swung into contact with the point 42, the apparatus, which is coupled into the outlet 32 by the plug 33 and cord 34, will be energized whenever the pin 43 connects the con- Near its outer end, each of the contact arms 38 and 33 carries a block of insulating 4 material 50, having an abrupt shoulder 5| set back some distance from the extreme end of the contact arm.

The dial plate4 has formed, adjacent its periphery, a circular series of holes 52 which are spaced apart by equal amounts, corresponding, as shown, to fifteen-minute intervals. The dial is also sub-divided, and provided with properly spaced numerals denoting each hour of the pericd which it consumes in making one full revolution, twelve hours being indicated in the illustrative structure shown in Fig. 1. An index mark 53 is carried by the front wall 2 of the casin preferably at a central point just above the dial plate 4, and the latter may be set so that the timeof day (or night) may be read by referring the graduations of the dial to this index point 53.

From Fig. 4 it will be seen that the free end portions of the contact arms 33 and 39 are disposed behind the uppermost portion of the periphery of the dial plate 4, so that when the metallic pin or plug 40 is inserted in one of the holes 52 so as to project from the rear face of the dial plate 4, the rotation of the latter will cause this pin to contact, first, the under surfaces-of the insulating blocks 53, 53, and then to travel toward the abrupt shoulders 5i of the blocks 50, as seen in Fig. 6; and as the pin passes these shoulders 5!, the arms 38 and 39 will snap suddenly into contact with the pin 49, as seen in Fig. 7, thus closing the circuit. Upon further rotation of the dial plate 4, the pin 43 will sprins the arms 38 and 39 upward because of their inclined relation to the path of the pin, and as the pin is carried beyond the ends of the arms 38 and 39, they will snap downward, opening the circuit. Thus the action of the arms 38 and 39 provides a quick make and also a quick break of the control circuit.

As shown, the contact portions of the arms 38 and 39 are long enough to maintain the circuit closed for approximately fifteen minutes. To keep the circuit closed for a longer period, the user can insert a number of the pins 40 in adjacent holes 52, the succeeding pins then holding the circuit closed for additional quarter hours. Or, if the mechanism is used to switch on a radio receiver connected to outlet 32, and it is desired to keep the radio operating after the pin 43 passes the ends of the arms 38 and 39, the knob 56 may be turned to swing the switch arm 44 onto contact point 54, which is connected by wire to the supply cable 35, thus by-passing the switch 38, 39 to maintain the radio in circuit. Such use of the time control might be made, for example, by setting the pin 40 in a position to start the radio at seven oclock in the morning, to awaken the user. Then, if he wished to have the program continued for a considerable period, he could swing the switch arm 44 onto contact point 54, as described. Or, to hear a particular program scheduled later in the day or evening, the contact pin 40 or an additional pin like it, would be set in the corresponding position by insertion in one of the holes 52 of the dial plate 4 so as to connect the radioin circuit in time to pick up the desired program. The commencement of the program would remind the user to then swingthe switch arm 44 over to the position in contact with the point 54 so as to keep the radio in operation as long as desired. 7

Since, when a particular contact pin 40 passes theextreme outer ends of the contact arms 38 and 39, it has no further eifect until the dial egime's be plugged into the dial'lplate atvarious positions to efiect switching operations at different times during the day orevening, if desired. To

provide for this, Ima'y supply a plurality of such plugs 60, as shownat 48 where they are supported insuitable openings in the front wall 2 of the casing when out'of service, and from whichany one'or more of-them may be removed for insertion, as desired, in the'apertures 52 of th dial-plated. Inadditionto the pin 49, already referred to, a second pin M is shown thus secured in operative position in the dial 4. While the pins 40 might be frictionally retained in the apertures 52 of the dial plate 4, I prefer to thread these apertures and to provide each of the pins 40 with a threaded portion 40 as seen in Fig. 10, and also with a sleeve or handle 490, which may be of insulating material, if desired, so as to avoid any possibility of electrical shock if the plug pin should be handled at a time when it is in position for contact with the arms 38 and 39.

On occasions, when the radio receiver is out of repair, or when, for any other reason, it is preferred not to use it as an alarm device, a small buzzer unit, such as that shown in Fig. 8, may be plugged into the outlet 32 in place of the attachment plug 33. This unit is shown as comprising a base with conductor prongs 5i projecting therefrom for engagement with the contacts 45 and 41 of the outlet 32, and with a buzzer mechanism including magnet coils 52 and an armature 83 secured to the upper side of the base 60. With the switch arm 44 adjusted into contact with the point 42, the buzzer will thus be actuated when the dial 4 has carried the contact pin ll] into engagement with the members 38 and 39, and the operation of the buzzer may be discontinued at will, and as soon as it has served its purpose, by merely swinging the switch arm 44 to the middle position, at which it is shown in Figs. 4 and 10.

It may be noted that the construction of the program dial of this device is rendered particularly simple because the dial plate 4 itself is made of insulating material, such as Bakelite or other plastic, thus permitting the metallic plugs 40, 40 and 40 to be inserted directly in the openings 52 of the dial plate without danger of grounding or short-circuiting therein. It is also feasible to construct a large portion of the device of Bakelite or other plastic material so as to avoid unnecessary use of metals at a time when they are in special demand for military uses. The housing or casing l, the front wall 2, the frame members 8 and 9, the posts I0 and the supporting panel II for the synchronous motor may all be made of such plastic material, as well as the angular connecting pieces shown in Fig. 2, securing thes parts. It is also practicable to form the gears I5 and i9 and the ratchet wheel 23 of Bakelite or plastic, and, obviously, the disk 20, switch knob 55, switch base 43 and the outlet 32 may be made of this material, leaving only a few small parts and connecting screws or bolts to be constructed of metal.

I claim as my invention:

1. In combination, a casing having a circular opening in one wall, a circular dial plate substantially closing said opening and mounted for rotation about its axis, a motor in said casing operatively connected to said dial plate and adapted to drive it at a predetermined, uniform rate, said dial plate having a plurality of holes 6 arranged ina circular series and i time-denoting gra'duations associated therewith on the dial *plate, a metallic plu-g insertable from outside the casing 'in any selected hole of the series in position to projeot into the casing'from the innerface "of the dial plateyand a pair of contactmembers "disposedside by-side in spaced 'relation to-each other," adjacent the plane of said dial plate and adjacent thepath ofthe 'metallic plug carried thereby,-said--plugserving to engage both contact -members at' a predetermined timeancl to disengage said m-embersas the dial plate-rotates.

2. The combination of a synchronous motorga cloclr dial plate with time-denoting graduations thereon, said plate being mounted for rotation about its axis, a gear train connecting said motor to the dial, said dial having a plurality of openings associated with said graduations and arranged in a circular series, a metallic contact element removably carried in a selected opening of the series and projecting from one face of the dial plate, a pair of contact members disposed side by side in spaced relation to each other, adjacent the plane of said dial plate and adjacent the path of said contact element carried by said plate, said element serving to engage both contact members at a predetermined time as the dial plate rotates.

3. In combination, a program dial of insulating material mounted for rotation, a motor operatively connected to said dial for rotating it, said dial having a plurality of holes arranged concentrically about its axis of rotation, a metallic plug insertable in any selected hole of the series in position toproject from the face of said dial, and a pair of resilient metallic contact arms mounted side by side in spaced relation to each other adjacent the path of said plug to form a switch, said plug moving into sliding contact with both arms and closing the switch as the dial rotates.

4. In combination, a program dial of insulating material mounted for rotation, a motor operatively connected to said dial for rotating it, said dial having a plurality of holes arranged concentrically about its axis of rotation, a metallic plug insertable in any selected hole of the series in position to project from the face of said dial, and a pair of resilient metallic contact arms mounted side by side in spaced relation to each other adjacent the path of said plug to form a switch, said plug moving into sliding contact with both arms and closing the switch as the dial rotates, said resilient arms extending obliquely across the path of the plug, whereby they are stressed by the advance of said plug and are sprung suddenly out of contact therewith as the plug passes the ends of the arms, thus effecting a quick break of the switch.

5. In the combination defined in claim 3, insulating blocks attached to said contact arms for initial sliding engagement with said plug as the dial rotates, the engaging surfaces of said blocks extending obliquely across the path of the plug, whereby the resilient arms are stressed by the advance of the plug and are sprung suddenly against the plug as the latter passes the ends of the insulating blocks, insuring quick contact.

6. In the combination defined in claim 3, the length of said arms beyond the point of initial contact with the plug being suflicient to continue the contact while the dial rotates through the angular distance between consecutive holes in said dial, and additional plugs insertable at will in consecutive holes to maintain the switch closed continuously for longer periods if desired.

- '7. In the combination defined in claim 3, insulating blocks attached to said contact arms for initial sliding engagement with said plug as the dial rotates, said arms extending beyond said blocks and snapping into contact with the plug as -15 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,980,700 Rosen Nov. 13, 1934 900,529 Hansen Oct. 6, 1908 1,313,440 Whittaker Aug. 19, 1919 614,982 Richard Nov, 29, 1898 1,596,859 Clyatt Aug. 17, 1926 

